Form of press.



H. E. BARR.

FORM OF PRESS.

APPLICATION FILED MAY 25. 1918.

Patented Dec. 24, 1916.

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HARRY EDSIL BARR. 0E ERIE, PENNSYLVANIA.

FORM OF PRESS.

Application filed May 25, 1918.

To all whom it may concern:

Be it known that I, HARRY EDsIL BARR, a citizen of the United States,residing at Erie, in the county of Erie and State of Pennsylvania, haveinvented a new and useful Form of Press. of which the. following is aspecification.

My invention has for its purpose the production of a machine for doingsuch work as forcing in or out of mandrels, arbors, shafts, bushing,pins, etc.,f0r pressing sheet metal into forming dies-for bending orstraightening metal and all such work common to the usual lrvdraulicpress. power press or hand press, etc.

The accompanying drawingl*igures 1 and 2shows the general constructionand principles of operation.

In Fig. 1 a base 1 having its upper face in the form of a substantiallyribbed platen for supporting the work, supports by means of posts 5- acylinder 3. A piston 4: operates in the cylinder, its lower portionreduced in diameter to form a heavy piston rod which extends through asuitable packing box and guide as shown. The piston rod portion isattached at its lower end to a crosshead 6 which is guided against posts5. A removable hardened steel nose 7 is provided as an abutment againstarbors, pins, etc, of small size which thus impose a heavy concentratedpressure on a small area. The removal of nose 7 permits substitution ofany desired piece such as a holder for a broach or punch. In case ofwork of considerable area, the nose is left out.

In Fig. 2 a reservoir 11 is provided, containing a liquid, preferablyoil, the reservoir having. a capacity equal to or in excess of thevolume of lower portion of cylinder at 8Fig. 1.

The press is intended to be operated by fluid pressure, preferablycompressed air at common shop pressures of 80# to 100#.

Referring to Fig. 2 a four way cock at 12, admits the air at E and inposition shown. passes it first through check valve 15 to top ofcylinder where it exerts its pressure on top piston 1Fig. 1. and tendsto move same downward. The downward movement of piston is prevented byliquid, preferably oil, in lower portion of cylinder at 8, and can occuronly upon opening of regulating valve 17, by the operator, thusSpecification of Letters Patent.

Patented Dec. 24. 1918.

Serial No. 236,653.

permitting the oil to be forced down into reservoir 11 per arrow G. Theoil enters reservoir at bottom or substantially so. The downward motionof piston having been completed at any speed desired by the operator,and under his immediate control by means of valve 17, it is preventedstriking the lower head of cylinder by reason of the connection at 10being at a suitable height above bottom of cylinder. The piston closesopening 10 by passing over it and no further oil can escape-check valve16 opening only in the reverse direction as per arrow B. It will beapparent that during the downward stroke of piston, with cock 12 inposition shown, the reservoir is vented as per arrow I to exhaust at F,thus allowing oil to enter reservoir freely. I

In making the reverse or upward piston stroke, the operator reversescock 12, connecting air supply at E with reservoir 11 as per arrow J,and connecting top of cylinder at 9 with exhaust F per arrow 1)- checkvalve 15 opening only in the reverse direction as shown. The airpressure on reservoir at or near its top, forces oil per arrow II andarrow B into bottom portion of cylinder under piston,regulating valve 17being closed. The piston is thus forced upward until it passes overopening 9, when it cushions and prevents striking upper head.

It will be understood that the piping shown is diagrammatic for thepurpose of illustration only and that the location of valves 12 and 17would in practice be placed for the greatest convenience of theoperator.

It will be understood also that in pressing sheet metal in dies, orother continuous production workparticularly requiring the hands ofoperator to be free, valves 12 and 17 may be operated by foot by asimple foot lever and connecting rods.

The advantages of this press are as follows Compared with such a machineusing fluid pressure. as air or steam to force the piston, etc., againstthe work-but not using a liquid under control in the opposite end ofcylinderthis press is positive in that it, will stop on the workingstroke as soon as regulating valve 17 is closed, due to theincompressible liquid thus prevented from further exit fromcylinder,-whereas the first mentioned type of press, with control onlypossible by shutting ofi the air pressure, would continue to move byexpansion of the full pressure air then in cylinder. This preventsworking to a given point unless a mechanical stop is provided-and isdangerous in pushing out work, when the resistance ceases suddenly, thuspermitting piston to slam to bottom of stroke.

Compared with a hydraulic press as commonly understood, this press ispractically unlimited in speed of working stroke-a feature of greatvalue in continuous production Work, yet it is also controllable to anyminimum of speed desired. It involves no excessive pressures withconsequent packing difficulties and is independent of all power sourcesexcept the common shop air supply,-

being thus, in the smallersizes entirely portable and extremelysimple,the portable hydraulic press requiring a pump therewith, operatedby hand or frequently by electric power.

Compared with power driven forcing presses, this press is'free from themechanical complications of gears, screws, etc., necessary in thusproducing a heavy pressure from rotative power applicationit isindependent. of all immediate power sources and is thus portable in thebroadest sensea feature of great value in' many plantsit is installedwithout accessory expense of counter-shafts, belts, etc.,it cannot beoverloaded by any act or negligence of the operator, so long as the shopair pressure does not'exceed the maximum for which press is designed,and this is fully guarded against by a simple safety valve on the airline to press. i

As compared with the common handwheel-and-screw press or the ratchetleverscrew-and-gear press, commonly used, this press eliminates manuallabor in creating the tonnage, is vastly. more productive because fasterand is not reduced in efficiency on continuous production, by the tiringof operator as when creating the pressure manually.

As compared generally with the types mentioned as' most commonly usedtoday, this press is a substantial improvement in being most broadly andeasily adapted to any class of forcing or pressing work required of sucha machine in the average asagna shop whether slow or fast, continuous orintermittent, portable or stationary, etc.

What I claim and desire to protect by Let- Y adapted to support workbeing pressed; a

piston in said cylinder, having an extension adapted to come agalnstsaid work; a reservoir containing liquid, as oil, in connection Withthat end of cylinder nearest in efiect t said abutment; acontrollingvalve in said connection; valve means of connecting end of cylinderfarthest in effect from abutment,

and the reservoir, alternately, with either 'air. pressure or withatmosphere, to cause saidpiston to reciprocate; the admission of airpressure to said farthest cylinder end forcing piston toward abutmentagainst resistance of said liquid passing to reservoir via saidcontrolling valve; and admission of air pressure to reservoir forcingliquid from same to end of cylinder nearest abutment thus moving pistonaway from abutmentsubstantially as shown and described.

2. In a press, the combination of a cylinder; an abutment opposedthereto and adapted to support work being pressed; a piston in saidcylinder, having an extension adapted to come against said work; areservoir containing liquid, as oil, in connection with that. end ofcylinder nearest in efiect to said abutment; a controlling valve in saidconnection; valve means of connecting end of cylinder farthest in effectfrom abutment, and the reservoir, alternately, with either air pressureor with atmosphere, to cause piston to reciprocate; the admission of airpressure to said farthest cylinder end forcing piston toward abutmentagainst resistance of said liquid passing to reservoir Via saidcontrolling valve; and admission of air pressure to reservoir forcingliquid from same to end of cylinder nearest said abut- HARRY EDSIL BARR.

Witnesses:

Jorm H. Nouns, DORMAN WEAVER,

